Raising By Coursing

Description

Raising By Coursing

In the illustration of the two pitchers, Fig. 97, it will readily be seen that it would be impossible to raise such shapes entirely by the first method, that of beating into a hollow block from the inside, as was described for the making of bowls, etc., altho nearly one-half of the raising of the pitcher can be done by that method. Fig. 94 shows the progressive steps taken in raising the large pitcher. No. 3 is about as far as it is possible to raise the shape by means of the first method, which we will distinguish by the trade term of "beating." With No. 4 the second method, known as "coursing," is resorted to. In this method the hammering is done entirely from the outside, with a broad faced neck hammer, and the pitcher is held on the round end of a No. 11 stake in the position shown in the drawing, Fig. 94. It must be remembered that in "coursing" (as in any other case where the shape is being changed), the metal must be softened by annealing whenever it gets hard and does not yield to the blows of the hammer.

The main object in "coursing" is to hold the metal in contact with the stake at about an inch below where the hammer is striking, and at the spot where the hammer is striking to keep the metal away from the stake, and to hammer it down to the stake thus closing in the metal and making the shape narrower. This will be understood better after a study of the drawing. The hammer blows are struck in rows all around the piece of work, starting at the bottom or where the shape starts to change, each row being about 1/2" higher than the preceding row until the top is reached.

It may be seen. Fig. 94, that there appears to be more metal in No. 6 than in No. 1. This apparent discrepancy is caused by the fact that the metal stretches and expands under the blows of the hammer. The mount of expansion is governed by so many factors that it is impossible to state it by any exact rule, but the approximate amount may be illustrated by the hollow handled pitcher, Fig. 97. It is 7" high and 5 1/2" across the base, which dimensions added together give a total of 19 1/2" from one edge of the metal to the other. The pitcher was raised from a circular disk of metal 14" in diameter. This shows that the metal stretched 5 1/2".

The neck of the small pitcher was formed by the "necking in" process illustrated on the bowls and jardineres in Chapter XV (Raising, Fluting, Paneling, Necking In).

Fig. 95. Lipping a pitcher.

Fig. 96. Bellying-hammer.

The lips of the pitchers may be easily formed by cutting the shape of the lip in the edge of a 3/4" board, fastening the board in the vise, and beating the metal down into the wooden lip with the neck hammer, Fig. 95.

After the pitcher or any other similar vessel is raised to nearly the desired form, it is often found necessary or desirable to drive out some part from the inside. This can readily be done by means of a tool that is known in the trade as a "bellying hammer," which is really not a hammer at all, but a piece of 1/2 round iron or steel slightly headed up at one end, bent into shape, with a file handle placed on the other end. The shape of this tool, and the method of using it, are shown in Fig. 96.

Another tool that is sometimes used for the same purpose is the "snarling iron," which is a piece of 1/2" round iron or steel about 16" long with about 2" at each end bent over at right angles in opposite directions. One end is fastened in the vise and the other end held firmly inside the pitcher against the spot that it is desired to drive outward, and a sharp blow is struck with the hammer on top of the snarling iron about 2" from the vise. This will cause the snarling iron to jump, and in springing back it will strike a sharp blow on the inside thus forcing out the metal. The shape of the "snarling iron," and the method of using, are shown in Fig. 98.